code: def test_introspection_lightning():
      """This test validates the scanner can find some PyTorch Lightning class within the provided files."""
      scanner = Scanner(
          str(
              os.path.join(
                  _PROJECT_ROOT,
                  "tests/tests_app/core/scripts/lightning_cli.py",
              )
          )
      )
      assert not scanner.has_class(Trainer)
      assert scanner.has_class(LightningCLI)
  
      scanner = Scanner(
          str(
              os.path.join(
                  _PROJECT_ROOT,
                  "tests/tests_app/core/scripts/lightning_trainer.py",
              )
          )
      )
      assert scanner.has_class(Trainer)
      assert not scanner.has_class(LightningCLI)
  
file_path: pytorch-lightning/tests/tests_app/utilities/test_introspection.py
imports: import os
  from numbers import Rational
  from lightning.app import LightningApp, LightningFlow
  from lightning.app.testing.helpers import _RunIf
  from lightning.app.utilities.imports import _is_pytorch_lightning_available
  from lightning.app.utilities.introspection import Scanner
  from tests_app import _PROJECT_ROOT
label_desc: Use image node_id 2 for calling a global function with example usage: test_introspection_lightning() without return types